Pneumatic suction device

ABSTRACT

A pneumatic suction device ( 1 ) comprises a main nozzle ( 10 ), through which the expansion of compressed gas is designed to generate, by means of a reaction, suction with a given vacuum and flow rate. At least one secondary nozzle ( 20 ), through which the expansion of the compressed gas is designed to generate, by means of a reaction, suction with a lower flow rate and a higher vacuum that those obtained with the main nozzle ( 10 ). Each secondary nozzle ( 20 ) is mounted to move between a passive position, in which the effective expansion of the compressed gas is performed by the main nozzle ( 10 ) and an active position, in which the effective expansion of the compressed gas is performed by the secondary nozzle ( 20 ).

The present invention relates to a pneumatic suction device, that is to say powered by air pressure and the Venturi effect.

Home, town, or industrial cleaning can be realized by means of more or less complex suction devices. But whatever the configuration selected, there are primarily two parameters to control, namely, the flow and the vacuum. These functional characteristics have to be adapted according to the application considered, and in particular this specific debris.

One knows in particular the suction device, known as vacuum, in which one uses the expansion of a pressurized gas to create vacuum and, consequently, to generate a phenomenon of a suction. In practice, the gas under pressure is generally the compressed air coming from a factory feeder system or from an internal compressor, for example.

Specifically, the compressed air is sent in a nozzle whose internal contour is adapted to generate, by the Venturi effect, a vacuum upstream of the most constricted section of the aforementioned nozzle when the compressed air slows downstream from the aforementioned section. This principle being known perfectly, it will not be described more here. One will recall simply that the flow and the vacuum depend, of course, on the form and dimensions of the nozzle, and in particular of its cross-section. In fact, with a large-sized nozzle, one will obtain a large volume of moved air but at the price of a relatively weak vacuum. To the contrary, with a nozzle of smaller size, there will be less flow but the vacuum will be then stronger.

This type of pneumatic suction device presents, however the disadvantage of a source of energy that has stable and constant characteristics (pressure, flow). To have fixed functional characteristics which constitutes only one compromise is not well adapted to the considered application. Thus, in practice, one often finds oneself with a suction device with too little vacuum and having a good flow, or having the opposite problem.

Also, the technical problem to solve, by the object of this invention, is to propose a pneumatic suction device comprising a nozzle, known as main, through which the expansion of a compressed gas is adapted to generate by an aspiration reaction a suction of given flow and vacuum, which pneumatic suction device makes it possible to avoid the problems of the state of the art by offering appreciably extended capacities of use, in particular to the level of the kind and consistency of these suctioned debris.

The solution with the posed technical problem comprises, according to the present invention, in what the pneumatic suction device comprises, moreover, at least a secondary nozzle movable to be substituted for the main nozzle, through which the expansion of compressed gas is adapted to generate a suction of a lower flow and a higher vacuum respectively than the flow and the vacuum obtained with the main nozzle, and in that each coaxial secondary nozzle with the main nozzle is assembled to be moved between positions, passive in which the effective expansion of compressed gas is achieved in the main nozzle and an active position in which the effective expansion of compressed gas is achieved by the aforementioned secondary nozzle.

One understands by effective expansion, that which is at the source of the suction generated inside the pneumatic suction device.

For the displacement of each secondary nozzle, any mobility means can evidently be envisioned.

The invention as it is defined presents the advantage of being able to vary the essential parameters of the suction according to the intended application, and in particular of the kind and/or the consistency of the product to be sucked up.

Thus, the same pneumatic suction device is able to collect effectively, also well substances needing at the same time a high flow and a limited vacuum, for example, dust or powdery matter, and substances requiring to the contrary a high vacuum and a reduced flow, for example, liquids of any viscosity.

The present invention also relates to the characteristics which will arise during the description which will follow, and which will have to be considered separately and according to all their possible technical combinations.

This description given by way of nonrestrictive example will explain how the invention can be realized, in reference to the annexed drawings:

FIG. 1 schematically represents a pneumatic suction device in conformity with the invention, in which the main nozzle is active.

FIG. 2 is a similar diagram to that of FIG. 1, but in which the suction device's secondary nozzle is active.

For reasons of clarity, like elements have been designated by identical reference numbers. Likewise, only the elements essential for the comprehension of the invention have been represented, and these, are diagramed without respect to scale.

FIGS. 1 and 2 illustrate a pneumatic suction device 1 functioning on air compressed to approximately 6 to 7 bars, which is provided here by the intermediary of an inlet 2. One also discerns equally the traditional means of distribution 3 which are charged to regulate the compressed air which is going to be allowed into the pneumatic suction device 1, with a view in particular to control of the final level of vacuum for obvious safety reasons. In a traditional way, the pneumatic suction device 1 is equipped with a nozzle 10, known as the main, which is made so that the expansion of the compressed air through it can generate, by reaction, a suction of strong flow and limited vacuum in the recovery can 50.

In accordance with the object of this invention, the pneumatic suction device 1 comprises, a secondary nozzle 20 which is made so that the expansion of the compressed air through it is able to generate, by a reaction, an suction of lesser flow but of greater vacuum. This secondary nozzle 20, coaxial to the main nozzle, in addition, is assembled so that it can move, between a passive position (FIG. 1) where it has the function of the expansion nozzle, and in which the effective expansion of the compressed air is carried out via the main nozzle 10, and an active position (FIG. 2), in which the effective expansion of the compressed air is carried out via the aforementioned secondary nozzle 20; the pressure of the compressed air is reduced by flowing through the rear channel 200 interdependent on the movements of the secondary nozzle.

In this particular embodiment, only selected by way of example, the main nozzle 10 and the secondary nozzle 20 are coaxial. Moreover, the secondary nozzle 20 is can be moved through axial translation in relation to the main nozzle 10. But, of course, other relative positioning and other types of mobility could be considered.

According to a characteristic of the invention, the pneumatic suction device 1 comprises, in addition, displacement means 30 which are arranged in a manner to be able to ensure the mobility of the secondary nozzle 20 between its passive position (FIG. 1) and its active position (FIG. 2), perfectly located to satisfy the “venturi” gas dynamics requirements.

In a particularly advantageous way, the displacement means 30 comprise a pneumatic cylinder 31 which is able to move the secondary nozzle 20 between its passive position (FIG. 1) and its active position (FIG. 2) in which the aforementioned secondary nozzle is positioned respectively away from and appreciably inside the main nozzle. This characteristic to some extent makes it possible to neutralize the main nozzle 10 in a reversible way, while coming to modify its internal section by interposition of the secondary nozzle 20 between the flow of compressed air and the aforementioned main nozzle 10.

In this example, the pneumatic cylinder 31 is composed of a hollow stem 32 which moves on a piston 33 assembled inside a bore 34; the distal end of the hollow stem 32 being joined to the secondary nozzle 20. In addition, the hollow stem 32 comprises, on the one hand, an inlet opening 35 communicating with the conduit 4 for feeding the compressed air, and on the other hand, an outlet opening, constituting a diffusion nozzle 36 emerging directly in the secondary nozzle 20. The hollow stem is used thus advantageously as a conduit to bring the compressed air into the interior of the pneumatic suction device 1 of the “venturi” type.

According to another characteristic of the invention, the pneumatic suction device 1 comprises control means 40 which are adapted to control implementation the bidirectional movement of the displacement means 30. Specifically, the control means 40 for the level of vacuum in the recovery can, comprises a valve which is able to inject air under pressure, via conduit 5, into the activating part 37 of the bore 34 of the pneumatic cylinder 31, thus translating the piston 33 and consequently, the secondary nozzle 20, to generate a greater vacuum, and this, without the injection of compressed air in the activation part 37 of the bore 34 of the pneumatic cylinder 31, the rest position of the piston 33 being, in fact, the withdrawn position of the pneumatic cylinder.

In accordance with another characteristic of the invention, the control means 40 are, moreover, adapted to determine the level of the vacuum generated inside the pneumatic suction device 1. In practice, the control means 40 communicate with the interior of the pneumatic suction device 1 by the intermediary of a conduit 6.

In a particularly advantageous way, the control means 40 automatically control the actuation of the displacement means 30 when the vacuum inside the pneumatic suction device 1 exceeds a predetermined threshold value or falls below this threshold value after operation with high vacuum.

As one can see it on FIG. 1, in practice, the pneumatic suction device 1 is configured by default to function with the main nozzle 10; the secondary nozzle 20 being in a passive position. The compressed air coming from the inlet 2 (flow f1) is allowed in the system (flow f2) under the control of the distribution means 3. The compressed air arrives then (flow f3) via the conduit 4 into the passive part 38 of the bore 34 of the pneumatic cylinder 31. It passes then by the inlet opening 35 into the hollow stem 32 that it traverses (flow f4) until emerging in the secondary nozzle 20 via the nozzle 36, whose expansion function is neutralized in the back position. Because of its high rate of travel, the compressed air is almost injected (flow f5) in the main nozzle 10 which is advantageously positioned on its axis. Once arriving in the main nozzle 10, the gas under pressure can then expand completely (flow f6) since the opening 11 of the aforementioned main nozzle 10 leads to the outside. The vacuum (flow f7) which is created inside the pneumatic suction device 1 extends then to the recovery can 50 equipped with a suction nozzle 51. The suction phenomenon which is then generated at the end of the suction nozzle 51 (flow f8) makes it possible to suck up matter 100 which will accumulate advantageously in the recovery can 50.

When, for example, an obstruction occurs or there is difficulty with the suction, the level of vacuum inside the pneumatic suction device 1 reaches a predetermined threshold value, the control means 49 are informed thanks to the presence of the conduit 6.

In accordance with FIG. 2, the control means 40 then will control the actuation of the displacement means 30 in order to activate the secondary nozzle 20. For that, compressed air will be injected via conduit 5 (flow f9) into the activation part 37 of the bore 34 of the pneumatic cylinder 31, which will cause the displacement of the piston 33. The secondary nozzle 20, consequently, will be translated in the direction of the main nozzle 10, until in its active position. The compressed air, which particularly always circulates in conduit 4, goes into the passive part 38 of the bore 34 and into the hollow stem 32, then it will drop in pressure at the level of the secondary nozzle 20 whose positioning makes the main nozzle 10 inactive. Because of the particular internal configuration of the secondary nozzle 20, the vacuum then generated is much greater, likewise the flow is decreased.

That advantageously makes it possible to continue the suction in an effective manner, with high vacuum, likewise if conditions render this operation, as already known, difficult. As soon as the level of vacuum in the can goes down again, following the removal of obstructions thanks to the high vacuum, the control means change state and move the secondary nozzle 20 to its initial, neutral position leaving only the main nozzle active, allowing suction with a large flow to begin again. 

1. A pneumatic suction device comprising: a main nozzle through which the expansion of a compressed gas generates by reaction a suction of a first flow and a first vacuum; at least a secondary nozzle through which the expansion of compressed gas generates by reaction a suction of a second flow and a second vacuum; the first flow being greater than the second flow and the second vacuum being greater than the first vacuum, the secondary nozzle being movable between a passive position, in which the effective expansion of the compressed gas is achieved by the main nozzle and an active position, in which the effective expansion of the compressed gas is achieved by the secondary nozzle.
 2. The pneumatic suction device according to claim 1, wherein the main nozzle and the secondary nozzle are coaxial, the secondary nozzle being movable along a translation axial relative to the main nozzle.
 3. The pneumatic suction device according to claim 1, further including a displacement means which moves the secondary nozzle between its passive position and its active position.
 4. The pneumatic suction device according to claim 3, wherein the displacement means comprises: a pneumatic cylinder which moves the secondary nozzle between its passive position in which the secondary nozzle is disposed away from the main nozzle and its active position in which the secondary nozzle is disposed appreciably inside the main nozzle.
 5. The pneumatic suction device according to claim 4, wherein the pneumatic cylinder is equipped with a hollow stem comprising, on the one end, an inlet opening communicating with a conduit for supplying the compressed gas, and on the other end, an exhaust nozzle disposed directly in the secondary nozzle.
 6. The pneumatic suction device according to claim 1, further including: control means for controlling in the two directions the activation of the displacement means.
 7. The pneumatic suction device according to claim 6, wherein the control means determine the vacuum generated inside of the pneumatic suction device.
 8. The pneumatic suction device according to claim 6, wherein the control means automatically control the activation of the displacement means when the vacuum inside the pneumatic suction device reaches a predetermined threshold value.
 9. The pneumatic suction device according to claim 1, further including a single source of energy consisting of compressed air.
 10. A suction device comprising: a venturi region in communication with a waste collection region; a first nozzle fixedly mounted adjacent the venturi region; a second nozzle movably mounted adjacent the venturi region for movement between a first position in which the first and second nozzles interact to create a venturi effect between the first and second nozzles and a second position in which the venturi effect is created at a compressed air inlet side of the second nozzle; a compressed air supply which supplies compressed air to the second nozzle inlet side in both the first and second positions. 